Spring retractable rule assemblies have been available commercially for many years. It is also known in the tape rule industry to provide a concavo-convex tape rule blade with a standard width dimension of ¼″, ½″, ¾″ or 1″, with a height dimension as high as 0.226″ as disclosed in U.S. Pat. No. 4,429,462 to Rutty et al. There always exists a need to provide a retractable rule assembly that presents new and innovative blade configurations.